Percutaneous drug delivery has attracted much interest in the field of local and systemic chemotherapy. However, most drugs themselves cannot penetrate the skin at high enough rates for therapeutic efficiency. Various approaches have been attempted to deliver drugs across the skin and additionally release the drug in a controlled fashion.
It is also desirable to develop a delivery system for delivering biologically active agents such as drugs, herbicides, fungicides, insecticides, etc. to target organisms, by oral, dermal, parenteral or foliar administration, with the agents still subject to controlled release. However, no satisfactory system has yet been developed, and the search continues for delivery compounds which are easily manufactured and have increased penetration rates for carrying drugs or other biologically active agents to a delivery site, with effective controlled release of the drug or agent through slow and controllable hydrolysis.